Research And Achievement Of Cnc Based On STEP-NC

Modern manufacturing industries demand computer numeric controllers,having higher level input languages than out data G-code,and less proprietary vendor dependencies.STEP-NC,a new data model for CAD-CAM-CNC chain,is expected to encompass the whole scope of e-manufacturing.The new data model formalized as ISO14649 is under development by ISO TC184 SCI and SC4 for the replacement of the old standard so-called G code,formalized as ISO6983 which has used since the 1950s. STEP-NC-based NC is open CNC with less proprietary vendor dependencies.Therefore, STEP-NC-based NC is the direction of development in modern manufacturing industries.The STEP-NC-based NC describes in this paper based on an open CNC system with PC + PMAC(programmable multiple-axis controller) models. In the PC + PMAC architecture, PC is the upper controller,which processes some higher-level and deeper-level computing tasks,while PMAC is the lower controller which integrates components such as on-1ine measurement unit,vertical feed unit,spindle unit and positioning unit into a rea1 open platform.Thereby,a real-time,high precision and frequency motion control is reallized.In this paper,the author first analyzes the characteristics of STEP-NC program. Then,based on STEP-NC-based NC requirements, the author describes the technologies related of development of the host computer system of STEP-NC-based NC by VC + +. In this host system,the decoding module tranlates STEP-NC program to the executable processing informations firstly, and then,the implementation module controls machine tools according to the information. Finally, the author describes the experimental platform of the host computer system of STEP-compliant NC.The experiment conforms the validity and effectiveness of this system.